• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.317-325
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• 2011

This study aims to develop the stance-control typed 4-bar linkage orthotic knee joint that replace the locked orthotic knee joint for the disabled with poliomyelitis and muscle weakness of lower limb. Unlike the existing stance-control orthotic knee joint, there are no needs of electric power, connecting circuit, bulky compomnets, etc, because this 4-bar linkage orthotic knee joint is controled by geometric locking. To evaluate the 4-bar linkage orthotic knee joint, a subject participated in this study who has been diagnosed with lower limb poliomyelitis and have used locked type orthotic knee joint. In the results of analysis of subject's gait using 3-dimentional motion analysis system, this 4-bar linkage orthotic knee joint provide the stability during stance phase and knee flexion during swing phase.

• Journal of The Korean Society of Integrative Medicine
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• v.1 no.2
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• pp.47-57
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• 2013

Purpose : The purpose of this study was to compare the Effects of Knee Extensor, Flexor Muscle Strength and Joint Position Sense in Squat Exercise on Variety Surface. Method : Subjuects were consisit of 30 male and female who had non disorder knee joint. we had devided 3 group(control group, balance pad group, and togu group) and we measured that knee joint $15^{\circ}/45^{\circ}$proprioception(position sense) and Peak Torque of knee extensor, flexor muslce at $60^{\circ}/sec$, $180^{\circ}/sec$ angular velocity. Result : First, knee joint $15^{\circ}$proprioception(position sense) of balance pad and togu group was significantly different after exercise(p<.05), but only balance pad group was significantly different at knee joint $45^{\circ}$. Second, knee extensor Peak Torque of balance pad and togu group was significantly different at $60^{\circ}/sec$, $180^{\circ}/sec$ angular velocity(p<.05). Third, knee flexor Peak Torque of balance pad and togu group was significantly different at $60^{\circ}/sec$, $180^{\circ}/sec$ angular velocity(p<.05). Conclusion : Squat exercises on the balance pad and togu were affects knee joint proprioception and muscle strength improvement. These results suggest that squat exercise on the unstable surface is effective for prevention of knee joint injury and functional activity.

• Journal of the Korean Society of Physical Medicine
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• v.4 no.1
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• pp.15-21
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• 2009

Purpose : The purpose of this study was to find the effect of ankle joint angle on knee extensor electromyographic activity following knee extension exercise. Methods : Ten male university students participated in the study. The subjects performed isometric maximal voluntary knee extensor contractions (MVC) and knee extensor EMG activity measured in with three different ankle joint angle. The EMG activity of rectus femoris(RF), vastus medialis(VM), vastus lateralis(VL) were measured using surface electromyography. Results : EMG activity of vastus lateralis following the change of ankle joint angle was shown statistically significant difference. Conclusion : Ankle plantar flexion position increase EMG activity of vastus lateralis during knee extension exercise.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1515-1517
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• 2008

The purposes of this study were to measure the ranges of motion in knee joint and during continuous passive motion(CPM) treatment and to computationally calculate joint angles at the knee joint dependent on the CPM machine design and its application. Four CPM machines and eleven candidates were recruited for this study. Experimental and numerical studies have been peformed to calculate the range-of-motion of CPM machines. From the experimental measurements, the average range of motions at the knee joint for the CPM machine #1, #2, #3, and #4 were lower than the manufactures suggested values due to improper alignments of the hip and knee joints to the CPM machines. Different design of CPM machine generated different outcomes of the ROM at the knee joints during CPM. The experiments and kinematic simulation in this study could be used to provide useful guidance in the treatment of CPM after joint surgery.

• Journal of Biomedical Engineering Research
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• v.29 no.3
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• pp.222-230
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• 2008

This paper introduces a method of estimating the knee joint moment developed during MVC. By combining the Hill-type muscle model and analytic results on moment arm and musculotendon length change as a function of hip and knee joint angle, the knee joint moment at a specific knee joint angle during MVC is determined. Many differences between the estimated results and the experimental data are noted. It is believed that these differences originate from inaccurate information on the muscle-tendon parameters. The establishment of exact values for the subject's muscle parameters is almost impossible task. However, sensitivity analysis shows that the tendon slack length is the most critical parameter when applying the Hill-type muscle model. The effect of a change of this parameter on the muscle length force relationship is analyzed in detail.

• The Journal of Korean Physical Therapy
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• v.31 no.5
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• pp.317-321
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• 2019

Purpose: To identify the effect of knee joint traction therapy on pain, physical function, and depression in patients with degenerative arthritis. Methods: In total, 30 patients with degenerative arthritis were randomly assigned to one of two groups: the experimental group, who underwent knee joint traction therapy, and the control group, who underwent general physical therapy (15 patients per group). Pain was measured using the visual analogue scale (VAS), physical function was measured using the Western ontario and McMaster universities osteoarthritis (WOMAC) index, and depression was measured using the Beck depression inventory (BDI). The VAS, WOMAC score, and BDI score were recorded before and after the 4-week treatment. Results: As a result of comparison within groups, the experimental and control group showed significant difference for VAS, WOMAC and BDI after the experiment (p<0.05). In comparison between the two groups, the experimental group in which knee joint traction was applied showed more significant change in VAS, WOMAC and BDI than the control group (p<0.05). Conclusion: This study showed that knee joint traction therapy was effective in improving pain, physical function, and depression in patients with degenerative arthritis.

• PNF and Movement
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• v.10 no.3
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• pp.25-31
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• 2012

Purpose : This study was intended to compare muscle activity in relation to knee joint angles on closed kinetic chain. Methods : A total of 13 subjects consisting of 5 adult males and 8 adult females were made to make movements maintaining knee joint angles at $30^{\circ}$, $45^{\circ}$ and $90^{\circ}$ on closed kinetic chain and the muscle activity occurring in their vastus medialis, rectus femoris and vastus lateralis was measured. Statistical data were analyzed using oneway ANOVA. Results : On closed kinetic chain, the muscle activity of the vastus medialis, rectus femoris and vastus lateralis increased the most at $90^{\circ}$ among the knee joint angles with statistically significant differences(p<0.05). Conclusion : On closed kinetic chain, it could be seen that as the angle of the knee joint increased, the muscle activity increased.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.13 no.1
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• pp.36-43
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• 2007

Purpose: An objective analysis and observations were to be done on hemiplegia patients that are wearing a walking support device, Stroke shoes. Their improvements in walking pace, the reduction of distance between the two knee joint, the increase of curve angle of the knee joint and their steps and the reduction of ankle joint upon swing phase were analyzed using a 20 walking analyzer. Methods: An examination was carried out to see the patients' communication skill and independent walking and then let them walk with the Stroke shoes on to get results before and after wearing it. Simi Reality Motion Systems GmbH (Germany, 2007) was used to analyze the results regarding knee joint and ankle joint angle changes of sagitta plane and coronal plane, stepping distances, distances between the knees and walking pace. Results: 1. The articulation angle of ankle joint during swing phase decreased and knee joint has shown a statistically significant increase in such value(p<0.05). 2. Only knee joint showed a significant increase in articulation angle during heel strike(p<0.05). 3. Knee joint showed a significant increase in articulation angle during toe off(p<0.05). 4. The distance between the two knees as well as their foot steps significantly decreased compared with when Stroke shoes were not worn(p<0.05). 5. Stroke shoes with FES have shown positive effects on the patients in improving their walking styles overall. (p<0.05). Conclusion: There was an improvement in rotation walking pattern by a reduction in the distance between the knees after wearing Stroke shoes with FES. Plantar flexion reduced that occurred in ankle joint during walking and flexion angle increased in knee joint, both of which improved foot drop which was a major problem in hemiplegia patients. Also it is believed that the device will have some positive influences on knee joint stiffening paralysis to aid in improving inefficient walking phases.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.1
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• pp.125-132
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• 2014

PURPOSE: This study aims to determine the optimal knee joint angle and hip joint angle for minimizing the cervical muscle tension and maximizing the muscle activity of the trunk during the bridging exercise for trunk stabilization. METHODS: The bridging exercise in this study included seven forms of exercise: having a knee joint flexion angle of $120^{\circ}$, $90^{\circ}$, $60^{\circ}$, $45^{\circ}$ and hip joint abduction angle of $15^{\circ}$, $10^{\circ}$, $5^{\circ}$. The posture of the bridging exercise was as follows. To prevent the increase of hyper lumbar lordosis during the bridging exercise, the exercise was practiced after maintaining the lumbar neutral position through the pelvic posterior tilting exercise. RESULTS: The abduction angles did not result in statistically significant effects on the cervical erector, external oblique, rectus abdominis and erector spinae muscles. However, in relation to the knee joint angles, during the bridging exercise, statistically significant results were exhibited. CONCLUSION: The knee joint angle affected the muscle activity of the neck muscle. The greater the knee joint angle, the lower the load placed on the neck muscle. In contrast, the load increased as the knee joint angle decreased. In addition, the muscle activity of the neck muscle and trunk muscle increased as the knee joint angle decreased.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.7
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• pp.723-729
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• 2012

Spring-like leg models have been employed to explain various dynamic characteristics in human walking. However, this leg stiffness model has limitations to represent complex motion of actual human gait, especially the behaviors of each lower limb joint. The purpose of this research was to determine changes of total leg stiffness and lower limb joint stiffness with gait speed in knee osteoarthritis. Joint stiffness defined as the ratio of the joint torque change to the angular displacement change. Eight subjects with knee osteoarthritis participated to this study. The subject walked on a 12 m long and 1 m wide walkway with three sets of four different randomly ordered gait speeds, ranging from their self-selected speed to maximum speed. Kinetic and kinematic data were measured using three force plates and an optical marker system, respectively. Joint torques of lower limb joints calculated by a multi-segment inverse dynamics model. Total leg and each lower limb joint had constant stiffness during single support phase. The leg and hip joint stiffness increased with gait speed. The correlation between knee joint angles and torques had significant changed by the degree of severity of knee osteoarthritis.